<?php
/**
- * Base class for resource loading system.
- *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
use Wikimedia\WrappedString;
/**
- * Dynamic JavaScript and CSS resource loading system.
+ * @defgroup ResourceLoader ResourceLoader
+ *
+ * For higher level documentation, see <https://www.mediawiki.org/wiki/ResourceLoader/Architecture>.
+ */
+
+/**
+ * ResourceLoader is a loading system for JavaScript and CSS resources.
+ *
+ * For higher level documentation, see <https://www.mediawiki.org/wiki/ResourceLoader/Architecture>.
*
- * Most of the documentation is on the MediaWiki documentation wiki starting at:
- * https://www.mediawiki.org/wiki/ResourceLoader
+ * @ingroup ResourceLoader
+ * @since 1.17
*/
class ResourceLoader implements LoggerAwareInterface {
- /** @var Config $config */
+ /** @var Config */
protected $config;
/** @var MessageBlobStore */
protected $blobStore;
}
/**
+ * @internal For use by ResourceLoaderStartUpModule only.
+ */
+ const HASH_LENGTH = 5;
+
+ /**
+ * Create a hash for module versioning purposes.
+ *
+ * This hash is used in three ways:
+ *
+ * - To differentiate between the current version and a past version
+ * of a module by the same name.
+ *
+ * In the cache key of localStorage in the browser (mw.loader.store).
+ * This store keeps only one version of any given module. As long as the
+ * next version the client encounters has a different hash from the last
+ * version it saw, it will correctly discard it in favour of a network fetch.
+ *
+ * A browser may evict a site's storage container for any reason (e.g. when
+ * the user hasn't visited a site for some time, and/or when the device is
+ * low on storage space). Anecdotally it seems devices rarely keep unused
+ * storage beyond 2 weeks on mobile devices and 4 weeks on desktop.
+ * But, there is no hard limit or expiration on localStorage.
+ * ResourceLoader's Client also clears localStorage when the user changes
+ * their language preference or when they (temporarily) use Debug Mode.
+ *
+ * The only hard factors that reduce the range of possible versions are
+ * 1) the name and existence of a given module, and
+ * 2) the TTL for mw.loader.store, and
+ * 3) the `$wgResourceLoaderStorageVersion` configuration variable.
+ *
+ * - To identify a batch response of modules from load.php in an HTTP cache.
+ *
+ * When fetching modules in a batch from load.php, a combined hash
+ * is created by the JS code, and appended as query parameter.
+ *
+ * In cache proxies (e.g. Varnish, Nginx) and in the browser's HTTP cache,
+ * these urls are used to identify other previously cached responses.
+ * The range of possible versions a given version has to be unique amongst
+ * is determined by the maximum duration each response is stored for, which
+ * is controlled by `$wgResourceLoaderMaxage['versioned']`.
+ *
+ * - To detect race conditions between multiple web servers in a MediaWiki
+ * deployment of which some have the newer version and some still the older
+ * version.
+ *
+ * An HTTP request from a browser for the Startup manifest may be responded
+ * to by a server with the newer version. The browser may then use that to
+ * request a given module, which may then be responded to by a server with
+ * the older version. To avoid caching this for too long (which would pollute
+ * all other users without repairing itself), the combined hash that the JS
+ * client adds to the url is verified by the server (in ::sendResponseHeaders).
+ * If they don't match, we instruct cache proxies and clients to not cache
+ * this response as long as they normally would. This is also the reason
+ * that the algorithm used here in PHP must match the one used in JS.
+ *
+ * The fnv132 digest creates a 32-bit integer, which goes upto 4 Giga and
+ * needs up to 7 chars in base 36.
+ * Within 7 characters, base 36 can count up to 78,364,164,096 (78 Giga),
+ * (but with fnv132 we'd use very little of this range, mostly padding).
+ * Within 6 characters, base 36 can count up to 2,176,782,336 (2 Giga).
+ * Within 5 characters, base 36 can count up to 60,466,176 (60 Mega).
+ *
* @since 1.26
* @param string $value
* @return string Hash
*/
public static function makeHash( $value ) {
$hash = hash( 'fnv132', $value );
- return Wikimedia\base_convert( $hash, 16, 36, 7 );
+ // The base_convert will pad it (if too short),
+ // then substr() will trim it (if too long).
+ return substr(
+ Wikimedia\base_convert( $hash, 16, 36, self::HASH_LENGTH ),
+ 0,
+ self::HASH_LENGTH
+ );
}
/**
$errorText = implode( "\n\n", $this->errors );
$errorResponse = self::makeComment( $errorText );
if ( $context->shouldIncludeScripts() ) {
- $errorResponse .= 'if (window.console && console.error) {'
- . Xml::encodeJsCall( 'console.error', [ $errorText ] )
- . "}\n";
+ $errorResponse .= 'if (window.console && console.error) { console.error('
+ . self::encodeJsonForScript( $errorText )
+ . "); }\n";
}
// Prepend error info to the response
/**
* Returns JS code which, when called, will register a given list of messages.
*
- * @param mixed $messages Either an associative array mapping message key to value, or a
- * JSON-encoded message blob containing the same data, wrapped in an XmlJsCode object.
+ * @param mixed $messages Associative array mapping message key to value.
* @return string JavaScript code
*/
public static function makeMessageSetScript( $messages ) {
*
* @internal
* @since 1.32
- * @param bool|string|array $data
- * @return string JSON
+ * @param mixed $data
+ * @return string|false JSON string, false on error
*/
public static function encodeJsonForScript( $data ) {
// Keep output as small as possible by disabling needless escape modes
* @throws Exception
*/
public static function makeConfigSetScript( array $configuration ) {
- $js = Xml::encodeJsCall(
- 'mw.config.set',
- [ $configuration ],
- self::inDebugMode()
- );
- if ( $js === false ) {
+ $json = self::encodeJsonForScript( $configuration );
+ if ( $json === false ) {
$e = new Exception(
'JSON serialization of config data failed. ' .
'This usually means the config data is not valid UTF-8.'
);
MWExceptionHandler::logException( $e );
- $js = Xml::encodeJsCall( 'mw.log.error', [ $e->__toString() ] );
+ return 'mw.log.error(' . self::encodeJsonForScript( $e->__toString() ) . ');';
}
- return $js;
+ return "mw.config.set($json);";
}
/**
dépôts / lhc / web / wiklou.git / blobdiff